1. Field of the Invention
The present invention pertains to data communication networks, such as long-distance telecommunication networks. More specifically, the present invention relates to testing network monitoring and/or control systems.
2. Related Art
A communication network serves to transport information among a number of locations. The information is usually presented to the network in the form of frequency-domain or time-domain electrical signals representing any combination of telephony, video, or computer data in a variety of analog and/or digital formats. A typical communication network has various physical sites, called nodes, interconnected by information conduits, called "links." Each link serves to carry data from one node to another node. Individual nodes contain equipment for combining, separating, transforming, conditioning, multiplexing/de-multiplexing, and/or routing data.
Digital cross-connect switches (DXC) are often provided at a site or node to switch traffic, electrically or optically, to an alternative link to alleviate congestion, avoid a link failure, or fulfill any other network configuration or restoration order. A central monitoring and/or control system (MCS) communicates with each node. Among other functions, the MCS monitors and controls digital cross-connect switching at nodes to route data through the network according to well-known network management and restoration techniques. The MCS is further responsible for dynamically establishing and breaking down logical trunk or channel connections between DXC nodes to provide dedicated point-to-point paths for customers.
The role of the MCS in a communication network, for purposes of (1) network management (i.e. traffic monitoring, control, and restoration) and (2) establishing dynamic trunk connections, has become even more vital as networks grow in size, complexity, and data capacity. The traffic of a single link through a digital cross-connect switch now represents a formidable volume of data--equivalent to tens of thousands of phone calls or more. Any delay or failure by an MCS to detect and respond to a link-failure can cause a significant loss in revenues for a network owner and loss of commerce and other benefits for the network subscribers. The demand for temporary dedicated lines continues to escalate as telecommunications customers send greater amounts of electronic data more often. Thus, it is increasingly important that a MCS be fully tested before it is relied upon to serve a communication network.
To flly test MCS performance, the MCS must be stressed by the behavior of an entire digital cross-connect network. As discussed above, a typical network can include hundreds or more nodes having digital cross-connect switching capability. Each digital cross-connect switch node often has many network node control links and ports. Each node control link in turn supports multiple communication sessions between the node and the MCS regarding audit and status states, alarms, network outages, etc. Given this complexity, to use an actual digital cross-connect network in a test environment to fully-test an MCS is impractical and cost-prohibitive.
Prior to the present invention, the behavior of a telecommunication switching network has not been fully emulated to test a MCS. Network behavior has not been emulated on any scale to test an MCS, especially in an environment where processing power is limited as in a personal computer system.
What is needed is a computer-implemented method and apparatus for emulating an entire digital cross-connect switch network to allow realistic MCS testing prior to actual implementation. The complete range of functionality of an MCS needs to be stressed. Communication between the MCS and a digital cross-connect network having hundreds or more network node control links needs to be emulated in the presence and absence of selected network failures and in the presence and absence of dynamically configured trunk connections.
For purposes of fully testing an MCS, it is further desired that digital cross-connect network behavior be emulated substantially in parallel with the processing of dynamic user-inputs and/or MCS commands identifying selected network node configurations, failures, and/or normalizations. It is also desirable that an MCS be fully tested inexpensively using a personal computer which emulates network behavior and responds to user and/or MCS inputs identifying selected network node configurations, failures, and/or normalizations.